All the regions are re-simulated at high resolution in 128 snapshots between redshifts \(z=0\)  and \(z=17\)  using three hydrodynamical codes: GADGETMUSIC [1]}, GADGET–X [2]}, and GIZMO-SIMBA [3]}. The first of the three is a standard smooth–particle–hydrodynamic (SPH) code while the other two are modern SPH codes. Apart from hydrodynamic simulations with astrophysical details, all the regions are simulated with a semi–analytical model or SAM using the codes Galacticus, SAG, and SAGE. The technical details such as initial conditions and box sizes related to these codes can be found in [4]}. The Three Hundred Project also provides multi–wavelength information of the clusters at the centre of each of the 324 regions, and their environment. These include mock X–ray, optical, gravitational lensing, radio, and SZ Compton parameter maps of each cluster. Clearly, this simulation provides a very detailed, all–rounded picture of clusters and as such, is a mass–complete, volume–limited sample for objects with \(M_{500} > 4.6\times 10^{14} \ h^{-1}{\mathrm {M}_{\odot }}\) , over a wide range of redshift.
